Estheti c Dentistr y Altere d passiv e eruption : A n etiolog y o f shor t clinica l crown s Arthu r H . Dol t IIF/J . Willia m Robbins* * Abstrac t TIK gingival complex plays a viitil role in the overall beauty of a smile. To predichibly cicliieve a siuress/iil esilieiic and fiuiciional resalí, llie denlisi nuisl be able in precisely preilid ¡he ¡reiiimeiil oiiicoine bused on biologic delerniinanls. Ill /lii.s ankle, the biulogic requirenieiiisj'or gingival licullh are discussed. In aüdilion. a dijfereniial diagnosis for excess gingival display and ireafnien! oplions for i/iis condiHiin are discussed. (Quintessenc e In t 1997:28:363-372.) Clinica l Man y peopl e witl i exces s gingiva l dispia y ar e unhapp y wit h thei r smil e bu t ar e unawar e o f th e option s availabl e fo r enhancemen t o f thei r smiles . I t i s importan t fo r demist s t o understan d bot h a differentia l diagnosi s an d [h e availabl e treatmen t option s fo r exces s gingiva l display . Introductio n Wt h th e increase d emphasi s o n tacia l esthetics , bot h patient s an d dentist s ar e developin g a greate r aware - nes s o f th smile . I n th e past , th e majo r dilemm a relate d t o gingiva l level s fo r th e restorativ e dentis t wa s th e managemen t o f th e patien t wit h lon g teet h secondar y t o periodonta l surgery . However , wit h th e evolutio n o f curren t periodonta l techniques , thi s proble m occur s muc h les s frequently . I n recen t years , mor e attentio n ha s bee n give n t o th e proble m o f excessiv e gingiva l display . anterio r maxill a wa s eithe r ignore d o r lengthene d prosthodontically . However , th e shor t clinica l crow n i s commonl y a resul t o f factor s othe r tha n inadequat e * Privat e Practice , Atlanta . Georgia . * ' A550dal e Professor , Depanmen l o f Genera l Deiilisiry . Universit y o f Texa s Healt h Scient e Cente r u l Sii n Anloniu , Sa r Anluiiio , Texai . Repri m reiiuests ; D r J . Wilia m Rubbins , Associat e Professor , Deparl - mcn t o f Genera l Dentistry , Universit y o Sa n Amonio . 77O J Floy d Cur l Drive , Sa n Amonio . Texa s 78284.7914 . Fax ; 2iO-567-.'44."1 . lengt h o f th e anatomi c crown . Commo n cause s o f shor t clinica l crown s includ e corona l destructio n resultin g fro m traumati c injury , caries , o r incisa i attrition , a s wel l a s a coronall y situate d gingiva l comple x resultin g fro m tissu e hypertroph y o r a phe - nomeno n know n a s altere d passiv e eruption . Successfu l treatmen t o f shor t clinica l crown s re quire s th e practitione r t o adequatel y diagnos e th e tru e etiolog y an d t o pla n a n effectiv e cours e o f treatmen t whil e givin g carefu l considérâ t i (i n t o th e biologi c widt h an d th e dentogingiva l junction . On e o f th e mos t commonl y overlooke d etiologie s o f th e shor t clinica l crow n i s altere d passiv e eruption . Curren t concept s o f recognition , diagnosis , an d treatmen t o f altere d pas - siv e eruptio n wil l b e discussed , alon g wit h a brie f etiologie s o f shor t elinica l crowns . Review of eruptive processes Active eruption ha s bee n defme d a s occlusa l move - men t o f a toot h a s i t emerge s fro m it s cryp t i n th e gingiva , Tlii s phas e end s whe n th e toot h make s contac t wit h th e opposin g dentitio n bu t ma y continu e wit h occlusa l wea r o r los s o f opposin g teeth . Passive eruption, o n th e othe r hand , i s apica l shif t o f th e demogingiva l junction . A s thi s occurs , th e lengt h o f th e clinica l crow n increase s a s th e epithelia l attachmen t migrate s apically . ' Th e passiv e eruptio n proces s ha s historicall y bee n characterize d b y fou r stages ' (Fi g 1 ) ; 1 . Th e dentogingiva l junctio n i s locate d o n enamel . 2 , Th e dentogingiva l junctio n i s locate d o n ename l a s wel l a s cementum . .Numbe r 6/199 7 36 3

Dolt/Robbin s Fi g 1 líeí l to right) Fou r classi c slage s o l passiv e eruption . Fi g 2 llelt lo right) Coslel' s fou r lype s o f alfere d passiv e eruptior r 1A , IB , 2A , an d 2B , 3 . Th e denlogingiva l junctio n i s locate d entirel y o n cemetilum , extendin g coronall y t o th e cemento - ename l JLinclio n (CH.I) . 4 . Th e denlogingiva l junctio n i s o n cementum , an d Ih e roo t surfac e i s expose d a s a resul t o f furthe r migratio n o f th e dentogingiva l junctio n o n th e cementu m (gingiva l recession) . Althoug h ther e i s debat e i n th e literatur e a s t o th e limit s o f wha t i s stil l considere d norma l physiologi c passiv e eruption , i t i s generall y agree d tha t exposur e o f cementu m i s considere d pathologic . Altere d passiv e eruptio n ¡als o know n a s ¡vlarckiipasaive entpiion o r delayed pa.'isive enipikm) occur s whe n th e margi n o f gingiv a i s malpositione d incisall y (occlusally ) o n th e anatomi c crow n i n adulthoo d an d doe s no t approxi - mat e th e cemenloename l junction.-"' ' Th e "normal " relatio n o f th e gingiva l margi n t o th e CE J i s usuall y considere d t o b e a t o r nea r th e CE J i n th e full y erupte d teet h o f adults.' ' Cosle t e ! al - classifie d case s o f altere d passiv e eruptio n int o tw o mai n type s accordin g t o th e relationshi p o f th e gingiv a t o th e anatomi c crow n an d the n subdivide d thos e classe s accordin g t o th e positio n o f th e osseou s cres i (Fi g 2) . Typ e 1 i s represente d b y th e presenc e ofth e gingiva l margi n incisa i o r occlusa l t o th e CEJ , wher e ther e i s a noticeabl y wide r ban d o f gingiv a fro m th e gingiva l margi n t o th e mucogingiva l junction . Th e mucogingiva l junctio n i s usuall y apica l t o th e alveola r cres t i n thes e cases . Typ e 2 i s represente d b y a gingiva l dimensio n fro m th e margi n t o th e mucogingiva l junctio n tha t appear s t o fal l withi n a norma l width . I n thi s type , al l o f th e gingiv a i s locate d o n th e anatomi c crown , an d th e mucogingiva l junctio n i s locate d a t th e leve l ofth e CEJ . Bot h type s 1 an d 2 ar e the n subdivide d int o 1 A , IB , 2A . an d 2B . I n th e A subgroups , th e alveola r crest - CE J relationshi p correspond s t o th e 1.50 - t o 2.0-m m distanc e accepte d a s normal . Thi s distanc e allow s fo r norma l insertio n o f th e gingiva l fibe r apparatu s int o th e cementum . I n th e B subgroups , th e alveola r cres t i s a t th e leve l ofth e CEJ . Thi s relationship , althoug h uncommo n i n adults , i s frequentl y observe d durin g th e transitiona l dentitio n tha t i s undergoin g activ e erup - tion . Th e significanc e ofth e alveola r crest-CE J distanc e i s relate d t o th e gingiva l fibe r apparatus . I n bot h typ e i an d typ e 2 cases , whe n th e alveola r crest i s locate d a t o r nea r th e CE J i n th e adult , ther e i s a lae k o f availabl e cementu m apica l t o th e CE J an d corona l t o th e alveola r cres t fo r th e insenio n ofth e collage n bundle s o f th e gingiva l fiber apparatus . Thi s prevent s th e norma l apica l movemen t ofth e attachmen t apparatu s a s th e final stag e o f eruption . I t i s no t uncommo n fo r alveola r bon e t o approximat e th e CEJ, ^ causin g a failur e o f apica l migratio n ofth e attachmen t apparatus . Som e investigator s hav e coine d th e ter m aliered adive eruption t o describ e thi s situation , i n whic h a coronall y place d attachmen t apparatu s result s fro m coronall y place d alveola r bone. ^ Altere d activ e eruptio n corre - spond s t o th e typ e I B altere d passiv e eruptio n i n Coslet' s classification . I n th e authors ' experience, typ e I B i s th e mos t commo n typ e o f altere d passiv e eruption . Clinically , a patien t wit h altere d passiv e eruptio n typicall y present s wit h shortene d clinica l crown s an d a smil e exhibitin g exces s gingiv a (ie , th e so-calle d gumm y smile) . However , th e characteristi c gumm y smil e i n a patien t wit h altere d passiv e eruptio n ma y b e 36 4 Quintessenc e Internationa l Volum e 28 , Numbe r 6/199 7

Doit/Robbin s mimicke d b y othe r conditions , includin g sfio n o r hyperactiv e maxitlar y tip . dentoatveola r extrusion , vertica t maxitlnr y excess , o r a combinatio n o f these . Ttier e i s n o predictabt e procedur e availabl e t o correc t th e sfior t o r hyperactiv e maxitlar y tip . How - ever , i t i s importan t t o communicat e th e diagnosi s t o th e patient , s o tha t treatmen t expectation s ar e realistic . Dentoalveoia r extrusio n generalt y occur s whe n th e maxLtlar y incisor s overcrupt . A s th e teet h continu e t o erupt , th e atveota r bon e an d gingiv a mov e dow n wit h th e teeth . Thi s result s i n ginglva t level s o n th e maxillar y incisor s tha t ar e significantl y mor e corona l tha n th e gingiva l level s o n th e adjacen t canines . Dentoalveoia r extrusio n i s mos t commonl y treate d wit h orthodonti c intrusion , althoug h i t ma y b e treate d wit h a segmenta l osteotomy . Vertica l maxillar y exces s occur s whe n ther e i s excessiv e growt h o f th e maxilla . I f vertica l maxillar y exces s i s suspected , a ceplialometri c analysi s ma y prov e t o b e a usefi.i l diagnosti c aid . Eve n i n th e cas e o f skeleta l maxillar y excess , i f th e clinica l crown s ar e shor t a s a resul t o f altere d passiv e eruption , i t i s recommende d tha t clinica l crow n lengthenin g b e accomptishe d prio r t o orthognathi c treatment . Thi s wil l hel p predic t th e postoperativ e smil e lin e an d th e fina l estheti c outcome . I t ha s bee n postulate d b y Prichard ^ tha t a n incisall y locate d gingiva l margi n ha s diminishe d protectio n from th e traum a o f ora l function , leadin g t o accelerate d gingiva l pathosis . Durin g initia l eruption , th e gingiva l maigi n i s o n th e conve x facia l surfac e o f th e enamel . I n thi s position , th e fre e gingiva l margi n i s no t protecte d fro m th e excursio n o f foo d durin g mastication . Factor s suc h a s thi s movemen t o f food , trauma , an d othe r debri s ma y contribut e t o chroni c inflammatio n o f th e bulbou s margina l gingiva - Thi s conditio n ma y persis t unti l th e gingiva l margi n migrate s t o th e cemento - ename l junction , wher e th e fre e gingiva l margi n i s protecte d b y subtl e corona l contours - I n altere d passiv e eruption , th e gingiv a doe s no t reced e t o thi s norma l positio n an d th e tissu e remain s o n th e conve x surfac e o f th e crown , wher e i t i s subjecte d t o chroni c irritation. ^ I t ha s bee n reporte d tha t gingiva l hyper - plasi a ma y develo p i n thes e patient s a s a resul t o f th e chroni c irritation, ^ Althoug h thi s ma y occu r i n rar e instances , th e gingiv a o f th e patien t wit h altere d passiv e eruptio n i s usuall y health y I n th e absenc e o f plaque . Restorario n o f teet h wit h altere d passiv e eruptio n pose s bot h ftincrional an d estheti c challenge s fo r th e dentist . I f n o attemp t i s mad e t o lengthe n th e clinica l crowns , difficult y ma y aris e i n obtainin g adequat e retentio n an d resistanc e form . I n addition , a dilemm a ma y exis t regardin g optima l placemen t o f crow n margins . I t ha s bee n demonstrate d tha t subgingiva l placemen t o f crow n margin s ma y lea d t o increase d plaqu e retentio n an d accelerate d periodonta l break - down , althoug h improve d esthetic s ma y b e achieved . Yet . i f th e clinicia n place s th e crow n margin s equi - gingivatt y n r sligtitt y subgingivaliy , th e margin s ma y late r b e unestheticall y expose d i f passiv e eruptio n continues. ' A commo n restorativ e erro r mad e whe n patient s wit h altere d passiv e emptio n ar e treate d i s th e placemen t o f margin s a t wha t woul d ordinaril y b e norma l anatomi c levels . Suc h margina l placemen t i n thes e patient s ma y inadvertentl y invad e th e biologi c widt h o f attachmen t becaus e oi'increase d alveola r bon e height , resultin g i n long-ter m inflammatio n an d com - promise d esthetics . Clinical diagnosis of altered passive eruption Th e firs t ste p i n th e diagnosti c proces s i s t o observ e th e patien t bot h i n repos e an d smilin g a natura l smile . I f ther e i s a n excessiv e displa y o f gingiv a durin g th e smile , furthe r diagnosti c dat a ar e required . First , th e lengt h an d activit y o f th e maxillar y li p mus t b e evaluated . Th e averag e lengt h o f th e maxillar y lip , i n repose , fro m beneat h th e nos e t o th e we t borde r o f th e maxillar y li p i s 2 0 t o 2 2 m m i n female s an d 2 2 t o 2 4 m m i n males. ^ I f th e gumm y smil e i s du e solel y t o inadequat e h p lengt h o r hyperactivity , n o treatmen t i s generall y indicated . I t i s importan t t o discus s thi s limitatio n wit h th e patient - Next , th e dentis t shoul d attemp t t o gentl y locat e th e ccmentoename l junctio n usin g a n explore r subgingi - vally . I f th e CE J i s locate d i n a norma l positio n i n th e gingiva l siilcus , the n th e paden t probabl y doe s no t hav e altere d passiv e eruption . I n thi s case , th e sho n teet h ar e probabl y du e t o incisa i wea r o r a variatio n o f norma l denta l anatomy - T o determin e th e approximat e amoun t o f missin g incisa i edge , th e dentis t shoul d measur e fro m th e CE J t o th e incisa i edg e an d subtrac t thi s numbe r fro m 10. 5 mm , whic h i s th e averag e lengt h o f a centra l incisor.' " Wit h thi s diagnosis , crow n lengthenin g ca n stil l b e performed ; however , thi s wil l resul t i n postoperativ e exposur e o f th e roo t surface . Whe n th e CE J i s no t detectabl e i n th e sulcus , a diagnosi s o f altere d passiv e eruptio n ma y b e made , an d cresta l bon e soundin g i s pedbrmed . Th e gingiv a i s anesthetize d an d a periodonta l prob e i s place d t o th e bas e o f th e sulcus ; th e measuremen t i s noted . Th e Quintessenc e Internation a i Numbe r 6/199 7 36 5

Doll/Robbin s prob e i s llie n pushe d throug h th e atiachmen t appara - tu s unti l th e alveola r cres t i s engaged , an d thi s measuremen t i s noted . I n mos t instances , th e distanc e fro m th e gingiva l cres t t o th e alveola r cres t wil l approxhriat e 3 mm ; whic h include s 1 m m fo r sulcu s depth , I m m fo r epithelia l attachmenl . an d 1 m m Ib r connectiv e tissu e attachment . Becaus e i t i s usuall y determine d tha t th e CE J i s approximatel y a t th e bas e o f th e sulcu s i n altere d passiv e eruption , th e measuremen t ca n b e use d t o determin e th e relationshi p betwee n th e CE J an d Ih e alveola r crest . Natur e require s approximatel y 2 m m fo r bot h epithelia l an d connectiv e tissu e attachmen t betwee n th e Ct J an d alveola r crest ; therefore , a determinatio n ca n no w b e mad e regardin g whethe r a gingivectom y and/o r gingiva l fla p wit h osseou s resectio n i s indicated . I t i s th e goa l o f crown-lengthenin g surger y t o expos e virtuall y al l ofth e anatomi c crown . O n th e completio n ofth e surger>' . th e margina l gingiv a shoul d b e situate d a t o r slightl y incisa i t o th e CEJ , an d th e measuremen t fro m th e gingiva l cres t t o th e alveola r cres t shoul d b e approximatel y 3 mm . Therefore , i f i t i s determine d tha t th e CE J i s a t th e bas e o f th e sulcu s and , b y bon e sounding , tha t th e distanc e fro m th e cres t o f gingiv a t o th e cres t o f bon e i s 3 mm , the n ostectom y an d a n apicall y positione d fla p wil l b e required . However , i f th e distanc e fro m th e cres t o f gingiv a t o th e alveola r cres t i s measure d a t 5 mm , an d ther e i s adequat e keratinize d tissue , the n approximatel y 2 m m o f gingiv a ca n b e simpl y remove d b y gingivectomy , leavin g th e require d 3 m m fro m gingiva l cres t t o alveola r crest . Treatmen t option s Gingivedoniy Whe n i t i s determine d tha t th e osseou s leve l i s appropriate , tha t greate r tha n 3 m m o f tissu e exist s fro m bon e t o gingiva l crest , an d tha t a n adequat e zon e o f attache d gingiv a wil l remai n afle r surgery , a gingi - vectom y i s indicated . Th e initia l incisio n shoul d b e lightl y score d o n th e gingiv a a t th e diagnose d ieve i o f th e CEJ . Th e initia l incisio n shoul d reflec t th e norma l gingiva l architecture , s o tha t th e highes t poin t ofth e gingiva ! margi n i s slightl y dista l t o th e cente r ofth e tooth . Th e initia l incisio n mus t b e precis e an d symmetric . I t i s difficul t t o accuratel y mak e th e scorin g incisio n whil e th e dentis t i s sittin g behin d th e patient ; i t ca n b e bes t accomplishe d whil e th e operato r stand s i n fron t o f th e patient . A sten t mad e o f eithe r acryli c resi n o r resi n composit e ma y b e use d a s a surgica l guid e fo r initia l incisions. " Th e dentis t ca n the n retur n t o th e sittin g posilio n an d complet e th e beveled , full-thicknes s gingivectom y incision . Tissu e i s onl y remove d fro m th e facia l surfaces . Th e papillar y tissu e i s ief t undisturbe d excep t fo r mino r blendin g wit h th e gingivectom y incision . Apically posiiioned ßap Whe n th e diagnosti c procedure s revea l osseou s level s approximalin g th e CEJ . a gingiva l fla p wit h ostectom y i s indicated . Th e initia l incisio n eithe r ca n b e don e a s describe d fo r th e gingivecfom y o r ca n b e mad e a s a sulcula r incision . I f th e gingiva l height s ofth e anterio r teet h ar e asymmetric , th e initia l incisio n mus t b e a gingivectomy-typ e incisio n s o tha t th e fina l tissu e contour s wil l b e symmetric . However , i f th e preopera - tiv e tissu e contour s ar e symmetric , a sulcula r incisio n ca n b e use d an d th e lla p i s the n apicall y repositioned . Th e incisio n cut s acros s th e facia l surfac e o f eac h papilla , leavin g th e papill a totall y intac t interproxi - mally , A full-thicknes s fla p i s rellecte d beyoti d th e muco - gingiva l junction , an d th e position s o f th e CE J an d cresia l bon e ar e visuall y verified . Ostectom y i s the n performe d s o tha t th e cresta l bon e i s approximatel y 2. 0 t o 2. 5 m m fro m th e CEJ . Th e facia l bon e i s firs t thinne d wit h a rotar y instrumen t suc h a s a diamon d o r carbid e bur . Th e remainin g bon e adjacen t t o th e roo t surfac e i s remove d wit h a n Oschenbei n o r Weidelstad t chisel . Th e bon y architectur e shoul d exactl y reflec t th e desire d sof t tissu e architecture . Th e gingiv a i s the n apicall y repositione d t o th e CE J an d sutured . I t i s commonl y necessar y t o thi n th e facia l gingiv a an d blen d th e fla p wit h th e papulae . Th e thinnin g i s bes t accomplishe d wit h a rotar y diamon d o r bur . an d th e blendin g o f th e fla p an d papill a ca n b e performe d wit h a single-wir e electrosurger y tip . Afte r th e tissu e i s apicall y repositione d t o th e CEJ . th e periodonta i prob e ca n b e inserte d through th e sulcu s t o ensur e tha t th e distanc e fro m th e crest o f gingiv a t o cresta l bon e i s 3 mm . Considerabl e variatio n exist s i n th e literatur e re - gardin g th e postoperativ e tim e necessar y t o establis h th e fina l gingiva l level s an d scallopin g prio r t o restoration , wit h estimate s rangin g fro m a fe w month s t o 3 years.'''-"" ' Som e author s hav e suggeste d tha t afte r initia l healin g o f th e junctiona l epithelium , a corona l reboun d ma y occur.'" * whil e other s hav e suggeste d a postsurgica l apica l migration . ' ^ Th e direc - 36 6 Quintessenc e Internationa l Volum e 28 , Numbe r 6/199 7

Dolt/Ro b bin s Fi g 3 a Ther e i s exces s gingiva l coverag e o f th e maxillar y anterio r teeth . Fi g 3 b Tli e maxillar y righ t centra l incise r i s 7 m m long . lio n o f healin g i s likel y a resul t o f th e tissu e positionin g a t th e tim e o f suturitig . Grea t car e mus t b e mad e t o repositio n th e tissu e wit h th e biologi c widt h o f attachmen t i n mind . Ther e i s generall y trtinima l tnovetnen t o f th e gingiva l cres t durin g healin g i f th e tissu e i s suture d i n th e correc t relationshi p t o th e alveola r crest . Afte r complet e healin g ha s occurred , tnitio r estheti c revision s i n th e gingiva l architectur e ca n b e accomplishe d wit h a scalpe l blade , eiectro - surgery . o r a laser . Orthodontic repositioning Whe n ther e i s a gingiva l asymmetr y o f on e o r multipl e anterio r teeth , orthodonti c eruptio n o r intrusio n ca n sometime s b e utilized . Th e mos t commo n nee d fo r orthodonti c repositiotiin g i s force d eruptio n o f a singl e anterio r toot h becaus e o f traumati c fractur e o f th e toot h o r becaus e o f previou s crow n margin s tha t hav e invade d th e biologi c width . Force d eruptio n i s pre - scribe d whe n i t i s determine d tha t crown-lengthenin g procedure s wit h ostectom y wil l resul t i n a gingiva l discontintiit y becaus e o f asymmetri c and/o r esthetic - all y unacceptabl e postoperativ e gingiva l levels . Th e amoun t o f desire d force d eruption , usuall y 2 t o 3 mm , tnus t b e predetermine d becaus e landmark s chang e durin g th e eruptio n process . I t shoul d b e accomplishe d quickly . 1 m m ever y 1 t o 2 weeks . Afte r completio n o f th e force d eruption , th e toot h i s place d i n retentio n fo r 2 t o 3 month s t o allo w th e bon e an d sof t tissu e t o mov e wit h th e tooth . Conventiona l crown-lengthenin g surger y i s the n accomplished . Whe n th e biologi c widt h impingemen t involve s interproxi - ma l bone , th e interdenta l papilla e mus t als o b e reflected . Ostectom y i s accomplishe d s o tha t ther e i s approximatel y 3 m m fro m th e cres t o f th e alveola r bon e t o th e propose d margi n o f th e final restoration . Th e tissu e i s the n suture d a t th e biologicall y an d estheticall y correc t level . Th e teet h tha t hav e under - gon e force d eruptio n shoul d the n b e place d i n retentio n fo r 3 t o 6 month s postoperativel y befor e final restoration s ar e placed.' ^ Orthodonti c intnisio n i s accomplishe d whe n on e o r severa l anterio r teet h hav e overerupte d (dentoalveola r extrusion) . Thi s mos t commonl y occur s whe n th e maxillar y anterio r teeth , alon g wit h th e gingival - alveola r complex , continu e t o erup t becaus e o f a lac k o f occlusa l stop s o n th e lingua l surfaces . A s th e teet h ar e orthodonticall y intruded , th e gingiva l alveola r comple x move s u p wit h th e teeth . Th e intrusio n i s complete d whe n th e gingiva l level s ar e comparabl e t o thos e o f th e adjacen t teeth . Intrusio n i s biomechanic - all y mor e difficul t an d require s significantl y mor e treatmen t time . Afte r orthodonti c intrusion , th e pa - tien t mus t b e place d i n long-ter m retentio n t o preven t relapse . Cas e report s Case 1 A 15-year-ol d gir l complained , "' I don' t lik e t o smile ; I sho w to o muc h gu m tissue " (Fi g 3a) . Examinatio n reveale d tha t th e lengt h o f he r maxillar y righ t centra l inciso r wa s 7. 0 m m an d tha t ther e wa s mino r incisa i chippin g bu t n o significan t incisa i wea r (Fi g 3b) . Th e gingiva l sulcu s wa s determine d t o b e 3. 0 m m dee p (Fig s 3 c an d 3d) , an d th e CE J coul d no t b e detecte d wit h a n explorer . Bon e soundin g wit h th e periodonta l QuintessericejolemauûnalU:iiuoj» ^ Numbe r 6/199 7 36 7

Dolt/Robbin s Fig s 3 c an d 3 d Th e sulcu s dept h i s 3 m m Fig s 3 e an d 3 1 Th e periodonta l prob e i s soundin g bon e t o th e alveola r crest , whic h i s 5 mm . Fi g 3 g Th e periodonla l prob e i s place d a t th e mucogmg i va l junction , demonstratin g adequat e attache d gingiva . prob e reveale d tha t th e measuremen t fro m th e gingiva l cres t t o th e alveola r cres t wa s 5. 0 m m (Fig s 3 e an d 30 . Th e nex t ste p wa s t o determin e th e amonn t o f keratinize d tissue . Th e periodonta l prob e wa s place d i n th e vestibul e an d move d coronall y t o determin e th e positio n o f th e mucogingiva l junctio n (Fi g 3g) . I t i s importan t t o kno w th e widt h o f keratinize d tissu e t o ensur e tha t adequat e keratinize d tissu e remain s afte r th e projecte d periodonta l surgery . I t wa s ais o note d tha t durin g a natura l smile , th e incisa i edge s o f th e maxillar y anterio r teet h wer e hidde n b y th e lowe r li p (se e Fi g 3a) . Base d o n thes e findings , i t wa s recommende d tha t th e patien t hav e a n orthodonti c evaluatio n an d diagno - sis . However , sh e chos e no t t o pursu e orthodonti c treatment . Estheti c crow n lengthenin g wa s als o dis - cusse d wit h th e patient . Sh e wa s tol d tha t wit h a 36 8 Quintessenc e Internationa l Volum e 28 , Numbe r 6/199 7

Dolt/Robbin s Fi g 3 h Vie w afle r completio n o f th e gingivectomy . Fi g 3 i I n th e gingivectom y procedure , 2 m m o f gingiva l tissu e wa s removed , leavin g th e require d 3 m m fro m gingiva l cres t t o aiveola r crest . Fi g 3 j Preoperativ e vie w Fi g 3 k Postoperativ e view . gingivectom y procedure , approximatel y 2. 0 m m o f toot h structur e coul d b e uncovered . Thi s woul d resul t i n a 9.0-mm-lon g maxillar y centra l incisor , whic h woul d b e 1. 5 m m shorte r tha n th e averag e I0.5-m m centra ! incisor . T o gai n th e additiona l 1. 5 m m o f lengt h woul d requir e a n apicall y positione d fiap wit h ostec - tomy . Afte r discussin g th e option s wit h he r mother , sh e chos e th e gingivectom y procedure , realizin g it s limitation s (Fig s 3 h t o 3m) . Case 2 A 30-year-ol d woma n complained , "M y fron t teet h loo k to o short " (Fig s 4 a an d 4b) . Examinatio n reveale d tha t th e maxillar y centra l incisor s wer e 8. 5 m m long , althoug h ther e wa s n o incisa i wear . Th e peri - odonta l examinatio n reveale d tha t th e sulcu s wa s approximatel y 1. 0 m m deep , an d th e CE J coul d no t b e detecte d wit h a n explorer . Bon e soundin g wit h th e Quintessenc e Infe r Numbe r 6/199 7 36 9

Dolt/Robbin s Fi g 3 i Preoperativ e view . R g 3 m Postoperativ e vie w Fig s 4 a an d 4 b Ther e i s exces s gingiva l coverag e o f th e maxiiiar y anterio r teeth . Fig s 4 c an d 4 d Th e periodonta l prob e i s soundin g bon e fro m th e gingiva i crest , whic h i s 3 mm . periodonta l prob e reveale d tha t th e measuremen t fro m th e gingiva l cres t t o th e alveola r cres t wa s 3. 0 m m (Fig s 4 c an d 4d) . Base d o n th e diagnosti c information , a diagnosi s o f altere d passiv e eruptio n wa s made . Th e projecte d estheii c outcom e o f th e surger y wa s demonstrate d t o th e patien t wit h resi n composit e overlays . Th e overlay s wer e constructe d o n a preopera - tiv e cast . Th e projecte d positio n o f th e gingiva l cres t wa s marke d o n th e cast ; th e highes t poin t wa s 10. 5 m m (th e averag e lengt h of a maxillar y centra l incisor ) fi'o m th e incisa i edg e (Fi g 4e) . Th e resi n composit e overlay s wer e constructe d i n tw o piece s an d place d ove r th e 37 0 Quintessenc e Internationa l Volum e 28 , Numbe r 6/199 7

Dolt/Robbin s Fi g 4 e Resi n composit e overlay s ar e fabricate d {show n o n th e patient' s righ t side ! t o demonstrat e th e approximat e amoun t o f toot h tha t wil l b e uncovere d wit h crown - lengthenin g surgery . Fi g 4 f Th e resi n composit e overlay s ar e trie d i n th e mout h (show n o n th e patient' s ngh t side ) t o demonstrat e th e projecte d outcom e o f th e surger y t o th e patient . Thes e overlay s ma y als o b e use d a s guide s durin g surgery . Fi g 4 g Th e periodonta i prob e i s pointin g t o th e cemento - ename l ¡unctio n Th e cres t o f alveola r bon e i s almos t coinciden t wit h th e CEJ . Th e margi n o f a porcelai n venee r (arrow! i s 2 m m incisa i t o th e CEJ . Fi g 4 h Th e periodonta i prob e i s pointin g t o th e CE J afte r ostectomy . Approximatel y 2. 5 m m o f bon e ha s bee n remove d onl y o n th e righ t centra l inciso r Margi n o f porcelai n venee r (arrow) . patient' s maxillar y anterio r teet h t o demonstrat e th e estheti c benefi t o f surger y (Fi g 40 - Th e patien t wa s tol d tha t th e onl y estheti c crown - lengthenin g optio n wa s a n apicall y positione d fla p wit h ostectomy . Becaus e ofth e exten t ofth e patient' s smile , th e crow n lengthenin g wa s onl y accomplishe d o n th e maxillar y anterio r teeth . Th e patien t initiall y presente d wit h porcelai n veneer s o n th e maxillar y centra l incisors . Althoug h th e gingiva l margin s wer e expose d durin g th e crown-lengthenin g surgery , th e estheti c blen d wa s acceptable . Therefore , n o addi - tiona l restorativ e therap y wa s require d (Fig s 4 g t o 4k) . Fi g 4 i Immediatel y postsurgica l view . Numbe r 6/199 7 37 1

Dolt/Robbin s Fi g 4 | Preoperativ e view . Fi g 4 k Three-mont h postoperativ e vie w afte r estheti c crow n lengthening . M o restorativ e therap y ha s bee n accom - plished . Summar y Severa l cause s o f shor t clinica l crown s hav e bee n discussed . A n ofte n undiagnose d etiolog y i s altere d passiv e eruption , whic h i s a failur e i n th e norma l apica l migratio n o f th e gingiv a and/o r attachmen t apparatus . Althoug h Cosle t an d coworkers - hav e classifie d fou r type s o f altere d passiv e eruption , a t th e presen t tim e ther e ha s bee n littl e investigatio n a s t o th e prevalenc e o f variou s type s o f altere d passiv e eruption , an d littl e i s know n abou t th e specifi c developmenta l cause s o f thi s phenomenon . Thi s discussio n ha s reviewe d curren t concept s i n recognition , diagnosis , an d appropriat e treatmen t o f patient s wit h altere d passiv e eruption . Reference s t . Gargiul o AW , e l al . Dimension s an d rotation s o f th e denlogiiigiva l junctio n i n hjmans . J Periodonto l i96i;32:261-267 . 2 . Cosle t JO . e t ai . Diagnosi s an d classificatio n o f delaye d passiv e eruptio n o f th e de n lo g ing i va l junctio n i n th e adull . Aiph a Omega n li)77;3:24-28 . 3 . Deli o Russ o NM . Piacemen t o f crow n margin s i n patient s wit h altere d passiv e eruption . I m J Periodo m Res l Den t 19S4;4 ( 1 ¡:59 - 65 . 4 . Woiff e GN , va n de r Weijde n FA , Spanau f AJ , d e Quince y ON . Lengtiienin g clinica l crt)wns- A solutio n fo r specifi c periodontal , restorative , an d estheti c problem s Quintessenc e In t l994i25;8l-88 . 5 . Evia n C , Cutle r S . Rosenber g E . Altere d passiv e eruption : Th e Lindiagnosc d entity . J A m Den t Asso c 1993;l24il07-110 . 6 . Ainam o J . Lo e H . Anatomi c characteristic s o f gingiva : A clinica l an d microscopi c stud y o f th e fre e an d attache d gingiva . J Periodonto l Í966;37;5-Í3 . 7 . Amsterda m MA . For m an d Functio n o f th e Masticator y System . Philadelphia : tJniversit y o f Pennsylvania . I99i . 8 . Prichar d JF . Advance d Periodonta l Disease , e d 3 . Philadelphia : Saunders , 1979:420 . 9 . Pec k S . Pec k L . Facia l realitie s an d ora l esthetics . In : McNatnar a J A ted). Esthetic s an d th e Treatmen t o f Facia i Form . Craniofacia l Orowt h Series , vo l 28 . An n Arbor . Ml : Cente r fo r Huma n Growt h an d Development , universit y o f Michigan , 1993:97 . ICI . AshM . Wheeler' s Denta l Anatomy , Physiolog y an d Occlusion , e d 6 . Philadelphia : Satinders . 1984:120 . l i Toivrisen d C . Resectiv e surgery : A n i sencein t 1993:24:535-542 . stheti c application . Quintes - 12 . Johnso n RH . Lengthenin g clinjca ] crowns . J A m Den t Asso c 1990 ; 121:473-476 . IÍ . d c Waa i H . e t al . Th e importanc e o f restorativ e margi n placemen t t o biologi c widt h an d periodonta i health . Par t 1 . [n t J Periodon t Res t Den t l99J;i3:46l-471 . 1 4 Bragge r U , Lauchenaue r D , Lan g N R Surgica l lengthenin g o f tli e ciinica l crown . J Cli n Periodonto l Í992;l9:5S-63 . 15 . Koi s 3. Alterin g gingiva l levels : Th e restorativ e connection . Par t 1 . Biologi c variables . J Esthe t Den t 1994:6:3-9 . 1 6 Alle n EP . Surgica l crow n lengthenin g fo r functio n an d esthetics . Den t Cli n Nort h A m 1993:37:163-179 . 17 . Kokic h VG . Enhancin g restorative , esthetic , an d periodonta l result s wit h orthodonti c treatment . In : Schluge r S , Yuodeli s R , Pag e RC , Johnso n R H (eds| . Periodonta l Diseases , e d 2 . Philadelphia - Le a & Febiger , 1990:120 . ' | ^ 37 2 Quintessenc e Internationa l Volum e 28 . Numbe r 6/199 7